Highlights of medical transaction data reporting, also referred to as the California Medical Data Call, are as follows:

Data to Be Collected

Medical transaction data on California workers’ compensation claims will be collected in accordance with the specifications of the Workers’ Compensation Insurance Organizations (WCIO) data record, “WCMED.” The WCMED record is being used in other jurisdictions to collect medical transaction data.

Eligibility Threshold

For transactions as of January 1, 2022, National Association of Insurance Commissioners (NAIC) Groups that write at least 0.5 percent of the California workers’ compensation market, as determined by written pure premium, are required to submit California Medical Transaction Data to the WCIRB. Market share is determined based on NAIC Group calendar year written premium at the pure premium rate level. Once required to submit Medical Transaction Data, an NAIC Group is required to report that data even if its California market share declines to less than 0.5 percent.*

Reporting Frequency and Duration

For transactions as of January 1, 2023, Insurer Groups are required to report California Medical Transaction Data to the WCIRB on a monthly basis. All transactions occurring during a quarter month are due to the WCIRB by no later than two months after the month in which the transactions occurred. (e.g., January transactions are due by March 31). Medical transactions on a claim are required to be reported for 30 years following the claim accident date.

Certification Testing

Each Insurer Group must complete a certification process before it is permitted to submit production medical data. The certification process begins by the insurer submitting a test plan to the WCIRB. If the insurer is using multiple submitters, the certification process must encompass each submitter. The WCIRB’s Medical Data Call Unit will work closely with Insurer Groups and their submitter(s) throughout the data certification process.

Reporting Media

California medical transaction data are to be submitted electronically to the WCIRB through the Compensation Data Exchange, LLC (CDX), which most insurers are currently utilizing to submit unit statistical data and/or policy data to the WCIRB. For more information, go to the CDX page on wcirb.com.

Permitted Exclusions

An Insurer Group may request to exclude up to 15 percent of its statewide business from the WCIRB medical transaction data reporting requirement, but only in rare circumstances and subject to WCIRB approval. For information on the process by which an insurer may request to exclude the reporting of a portion of its California business, refer to WCIRB Form 102 California Medical Data Call – Business Exclusion Request Form and Guideline for Completing Form 102 or contact the Medical Data Call Team at [email protected].


To enroll in the Medical Data Call, eligible Insurers must complete Form 101, Insurer Group Profile and Contact Designation.

Data from Third Party Entities

Insurers may designate a third party to act on their behalf. The Insurer Group is responsible for data quality, regardless of who submits their data. For additional information, go to the Using Third Parties page on wcirb.com.

*For transactions prior to January 1, 2022, the eligibility threshold was 1 percent of the California workers’ compensation market, as determined by written pure premium.